I won't try for the first, but there was folk-rock way before the term was coined. Johnny Horton did "The Battle of New Orleans", Jimmie Rodgers (not THE Jimmie Rodgers) did "Kisses Sweeter Than Wine."

I don't know where you want to put skiffle but Lonnie Donnegan did the whole Leadbelly songbook with drums and electric guitar before the Animals did "House of the Rising Son."